BEIJING -- Published author and qualified physicist Lin Degang seems unusually thoughtful for a Chinese entrepreneur. The founder of Oyeah.com.cn, China’s most popular online sex toy and lingerie retailer, Lin looks out over Beijing’s central business district from his 27th floor office, chain smoking from a red-colored pack of Yuxi-brand cigarettes.

"When I tell people what I do, they often call me a hooligan,” Lin said, filling Oyeah’s glass-walled conference room with another puff of smoke.

Lin founded Oyeah in 2003 after majoring in physics at Nankai, an elite Chinese university, ignoring his relatives’ advice to become an academic. The firm delivers erotic products to every major city in China, and its annual revenue is reported to be equivalent to over two million dollars. “Female vibrators are our best selling product, followed by lingerie,” Lin said.

Reports of the opening of China’s first sex toy store in 1993 reached a teenaged Lin, who read about it in his hometown’s local paper. By the late 1990s, similar establishments, known euphemistically as “Adult Goods Stores” sprung up all over China. “When we started the market was still dominated by small retailers,” Lin said.

Those stores were usually cramped and dusty, and sold products of dubious safety. “It wasn’t seen as a respectable trade, so most of the store owners were poor, with low budgets,” Lin said. So Lin took the trade online, partnering with a sex toy wholesale market he found in one of Beijing’s ancient “hutong” alleyways, taking orders and contacting deliverymen from his bedroom. This business was a success, and Oyeah soon acquired a staff of five.

A typical "adult goods store" in China.

But running an adult-oriented website can be an embarrassment in China, where sex is still widely seen as a dirty topic, unfit for polite conversation. Lin didn’t feel comfortable with his work, and soon handed managerial responsibility for Oyeah to a female cousin. “I thought the industry was too low-brow,” he wrote in a recently published book. “It was my negative attitude towards sex which pushed me out of the business.”

Lin experienced an epiphany when he read about Ann Summers, a British chain which sells sex products in slickly-designed, fashionable stores. “It was a huge shock to see that a company in the industry could be so professional,” he later wrote. In the meantime, Lin’s attitude to sex also changed. “I began to see sex as essentially connected to love, not something dirty,” he wrote.

Lin returned to Oyeah with a plan to target urban professionals, and especially couples. Oyeah’s vibrators and lacy underwear are shipped to an emerging class of Chinese yuppies, who value the finer things in life. “Our customers are the kind of people who enjoy red wine [a symbol of status in China],” Lin said. The change of approach has worked: Oyeah’s sales grew 50 percent annually in recent years, Lin said. He estimates that more than 70 percent Oyeah’s customers are men, buying gifts for their wives or girlfriends.

The cover of Lin's book "Bring a Romance to Adults."

The success of Oyeah is a sign that attitudes towards sex in China are slowly liberalizing, according to Lin. “Younger generations have a healthier attitude towards sex than the previous ones,” he said.

After Lin wrote an account of his business career which was downloaded over a million times, a minor bidding war broke out between publishers. The resulting book carries the English title “Bring a Romance to Adults,” and combines the popular-in-China genre of business memoir (how to found and run a successful company) with Lin’s thoughts on sex. “It’s about being open about sex, and clearing up people’s misunderstandings,” he said.

The book also promotes Lin’s view that sexual experimentation is the best way to strengthen monogamy. “My philosophy is about being conservative in number of partners you have, but being experimental in how you have sex,” he said, a nod towards the prevalence of mistresses and extra-marital affairs in China.

Lin estimates that Chinese sex toy sales double every year, but only around three percent of Chinese couples currently use sex toys. “It’s still a niche market,” he said. Oyeah’s central offices take up some of the most expensive real estate in Beijing, but Lin doesn’t lead an extravagant lifestyle, often taking the subway to work. “I own two Peugeots, but I never learnt to drive,” he said.

Lin is fifty thousand characters into a second book, but finds it hard to combine juggle writing and managing the ever-growing Oyeah empire, which will expand into several high-street shops this year. “Writing is about self expression, and changing people’s attitudes” he said. “Sex is a basic element of human life, and my work is about helping people to improve that part of their lives.”